Decentralised Coordination of Web Services for B2B Integration

Web Services technology is becoming the de-facto standard for integration of legacy applications within an organisation and for cross organisation enterprise application integration (B2BEAI). Much work has gone into specifying Web Services functionality using workflow like techniques (BPEL4WS, WSCI, WSFL, XLANG) and production of software to enact such descriptions. However, most of this software relies on one central server to enact the workflow which may be a performance bottleneck when the server is under high load. In this paper we outline a workflow specification language and present a sample implementation of a workflow engine which allows distributed enactment of workflows. Distributed enactment removes this potential bottleneck and can also reduce data transfer. We also describe how the workflow engine promotes message based integration, simplifying the problem of application integration across organisational boundaries.